mgoddard1

A blown LIM gasket will suck air at idle and blow gas and oil vapors under boost which could explain all that black soot. I had that happen on a much smaller scale when my original paper LIM gasket blew out a 1/2" gap in the far bottom left corner. But, you won't know for certain until you pull the LIM, turbos, and the turbo manifold. The turbo manifold gaskets are much less likely to leak since they're made of metal.

a3dcadman

iTrader: (1)

Can an exhaust leak develop between the intermediate housing and a rotor housing? If so, would that condition leave a sooty deposit as in the pics Ive posted? Would that condition also result in a lower compression?

Here are some pics of the exhaust manifold and gaskets and the turbo and gaskets. There doesnt appear to be an exhaust leak. One of the turbo gaskets has a small crack. Ive included view of both sides of the gaskets and the engine block.

a3dcadman

iTrader: (1)

more pics

a3dcadman

iTrader: (1)

"Can an exhaust leak develop between the intermediate housing and a rotor housing? If so, would that condition leave a sooty deposit as in the pics Ive posted? Would that condition also result in a lower compression?"

There really was no definitive sign of exhaust leak. If I have time I will pull the LIM tonite and run a new compression test . But the quoted question above has me worried since I could not find any other source for the leak. The LIM appears to have an open channel that runs up between the block and the LIM. Situated in this channel is the seam between the rotor housing and intermediate housing. Looks like a possible source for the soot.

Thoughts on a leak between these engine sections?

thanks,
chuck

Mahjik

iTrader: (1)

If you really had that kind of leak between the engine housingsyou would have more problems than what you are reporting in this thread.

mgoddard1

Your turbo gaskets look fine but there's quite a bit of burned off oil or soot on your secondary turbo. The oil/soot may be caused by your potential LIM leak but I'd make sure the banjo bolts on the oil intake line on your turbos are torqued properly.

a3dcadman

iTrader: (1)

With the exhaust manifold off, I am able to feel the rotors and the apex seals. All the seals feel fully intact but dont seem to move much (up & down). I was surprised at the amount of black crud inside the housings. How much movement should there be for the apex seals - min to max?

Since there is a significant difference in compression between the the front and back rotors, I decided to decarbonize the rotors and housings using ATF. Just putting the ATF in made a big difference on compression levels. Perhaps the difference in compression Im experiencing is because of reduced range of motion in the apex seals.

Is there a more effective product for decarbonizing that would be available at the local auto parts store and will not adversely affect other engine components.

Will finally get around to pulling the LIM and doing another compression test this afternoon.

chuck

mazpower

iTrader: (4)

I've seen the black soot on the LIM from an exhaust leak on my FD, when a manifold stud broke. Nothing critical, just leaves some soot on the LIM. Even though your gaskets look intact, you may have a warped exhaust manifold or it could have just been slightly loose.

It is a good sign that you can push the seals in and out. You could have a chipped apex seal, where it meets the corner apex seal piece. You wouldn't be able to see this through the port - I've got personal experience on this one, having popped several engines over time with Atkins seals, which chip the very edge and look & feel fine through the ports. Judging from your compression numbers, I doubt you have a bad seal. It is alarming that your rotors have the compression discrepancy they do.

As for the soot, that's typical of a higher mileage rotary, nothing to be alarmed at.

You had asked what the rectangular ports in the LIM are for. Those are exhaust ports, used by the EGR valve in the manifold to dump exhaust gases in the intake. They originate from the engine's exhaust ports and lead up to below the intake ports.

Back to the rotor difference. I had an engine in my older '87 TII that had a big discrepancy in compression between the front and rear. When it was cold, it would sound like it was running on one rotor for the first 10 seconds of startup. This occured until it no longer wanted to start - months later - and turned out to be a marginal coolant seal.

RotorJoe

The others are Seafoam, MMO and water. Not sure which one works the best though. I've used water and MMO in the past but I was just dumping (letting the engine suck the stuff in) the MMO and the water in while I held the idle at 1500-2000 RPM.

a3dcadman

iTrader: (1)

You hit it right on the head. Blown paper LIM gasket at the lower corner. Now the question is this: will that cause the idle problem and running hot problem Im experiencing. Heres some pics to look at.
I flushed the engine last nite with C_FOAM, INTAKE MANIFOLD CLEANER, and finall rinsed out all the crud with water followed by turning the engine over with starter and compressed air drying. I am still planning on running the compression test for those interested, just havent gotten around to it yet.

Reassembly with be slow and meticulous with cleaning of all parts, replacing fuel hoses, vacuum hoses, and coolant line hoses. All solenoids will be vacuum tested. Im pulling the injectors tomorrow for servicing and flow tesing. There are several pieces that I will be painting with a ceramic impregnated hi-heat paint and a couple of aluminum items I am going to sand and polish.

I will continue posting my progress with pics and any other info that may be helpful and/or pertinent and hopefully at the end of this process the problems will be rectified.

thanks
chuck

a3dcadman

iTrader: (1)

Im currently in the process of changing over all the vacuum lines to silicone. All the wiring has a black loose fitting sleeve most of which has become very brittle and shatters when moving or bending it.

For those that have done the hose mod, what did you use to cover the electrical wiring? Did you wrap with electrical tape? Did you slit the vacuum hose and use it to cover the wiring? Appreciate any ideas on ways to cover the wiring.

thanks,
chuck

Mahjik

iTrader: (1)

Don't use standard electrical tape; it won't take the underhood heat that well. Use some high temp tape like this:

X-Treme Tape

a3dcadman

iTrader: (1)

I picked up a few rolls of the extreme tape from Summit. Its high quality stuff compared to what I was able to procure from my local auto parts store. It is much thicker, more durable and resists tearing, and easier to work with than the thin flimsy auto parts store product.

Since my last post, I have been disassembling the various sub assemblies, repairing, painting, and cleaning as necessary. Some of the aluminum parts ie. thermostat housing have been sanded and polished. Ive replaced all the fuel hoses (mazda kit), vacuum lines (hose tech silicone), and coolant hoses (mazda kit).

The injectors were serviced and flow tested by witchhunter performance (www.witchhunter.com)at $15 each which includes a readout for resistance, leak test, spray pattern, static flow, pulsed flow, cc/min and balance. Not a bad price for a one day turnaround.

A note on removing the fuel injectors. They took a little work getting them out of their holes, requiring a lot of prying and twisting. Didnt want to screw any of them up considering the hundreds of dollars each that they cost. When they were out, I pryed out the o-ring seals and what I thought was a secondary seal or part of the one I had just pulled. Turns out they were part of a plastic component that protrudes into the fuel rail and acts as some type of deflector for incoming fuel. This secondary o-ring was part of this little plastic deflector. Consequently, they got trashed with a replacement list price cost of 2x $33.93 and 2x $29.56. Ray got them to me for $69 for all four.

I am going to run the compression test again tonight before I start reassembling the engine.

chuck

CantGoStraight

Just curious if you have the parts numbers for the hose kits. I understand it's cheaper than one at a time purchase. Thanks, Jack

Mahjik

iTrader: (1)

If you have time, post your before and after numbers.

Mahjik

iTrader: (1)

I believe this is the part number for the fuel hose kit (at least that's what's on my receipt ): N3A1-13-S70A

DaleClark

iTrader: (55)

Just FYI, there IS exhaust gas running through the lower intake manifold. It comes up through the center iron, through the square hole, and to the EGR valve. The EGR passage was likely blowing by a bit, giving you that soot on the outside.

The exhaust gas goes to the EGR valve, and when the EGR is open, it passes some of the gas into the intake manifold to add to the intake air stream.

Dale

a3dcadman

iTrader: (1)

Would the LIM gasket being blown at the lower left corner cause the idle issues, hot start problems, and hot running that I was experiencing?
chuck

DaveW

Idle issues: Yes
Hot start problems: Yes

Both due to leaning out the mixture affecting one rotor more than the other.

Hot running: I don't know why it would. That doesn't mean it couldn't, but I don't see a direct connection.

jacobcartmill

iTrader: (6)

it sounds to me like you have a cracked apex seal. i have blown 4 motors and am somewhat of an "expert" on blowing engines


but then again, the video clip doesnt work. so if someone could re-host it, i could probably help troubleshoot this

a3dcadman

iTrader: (1)

Ive been buried with my job work and homework and a bout with the flu so progress has been slow lately. Have finished up most of the electrical wiring re-wrap with the EXTREME TAPE which was recommended by mahjik. Awesome stuff. All the coolant lines from the kit are placed. Havent found where all of the fuel lines from that kit go yet.
Ive attached a copy of my injector servicing for those that are interested.
chuck

a3dcadman

iTrader: (1)

I did the compression tests again. This time the UIM, LIM, turbos and exhaust manifolds were off the engine. During the last couple of weeks, I ran the procedure for cleaning out the carbon buildup several times.

results:
front rotor - produced 85 psi per pulse and 85 psi total accumulated pressure.

rear rotor - produced 100 psi per pulse and 125 psi total accumulated pressure.

While decarbonizing the rotors, I was able to get the apex seals to move in and out on the rear rotor but was not able to get comparable movement from the front seals.

As evidenced by the numbers, the decarbonizing process has given me positive results and hopefully will yield even more when I can actually start the engine and blow out more of the crud.

chuck

a3dcadman

iTrader: (1)

Finally got the engine put back together, excluding the turbo piping and the air cleaner box and hoses. I decide to see if she will fire up before putting all the remaining plumbing on. I crank the engine over with fuse pulled so that I dont get any spark yet to get the oil circulating. Then I replace the fuse and check for fuel pump function, everything is a go. She fires up after 2 or 3 revs. There is a ton of smoke coming out of the exhaust and smoke from the parts I painted, but she seems to be running okay considering that the intake and turbo plumbing is still not in place.

Last night I finish installing all the remaining components. I then try to start the car and it tried once and that was it. Would only fire intermittently. Im checking my plugs in case they got fouled from last nights start up and will run a few other tests.

Any ideas on the start issue would be appreciated.

chuck

RotorJoe

Well good job buddy.

How long was the motor running the first time you started it? Remember, compression will be slightly lower on a fresh rebuild. So it may have trouble starting and you may need something in there to help build a touch more compression for the first few starts.

Once you're up and running maybe we can go for a drive sometime. We'll see if we can't get a few group meets around the local area.

manny34711

change plugs